1. Field of the Invention
The present invention relates to an air conditioner for a vehicle.
2. Description of Related Art
In a conventional air conditioning unit for a vehicle as shown in Japanese Utility Model Laid-Open No. Hei 2-15508, a plate-shaped sliding door as an air mixing door slides in a direction crossing the cool air and warm air passages to adjust the mixing ratio of the cool air and the warm air. In such an air conditioning unit for a vehicle, it is necessary to fully close the cool or warm air passage with the sliding door in the maximum cool mode where no air is sent to the heater core and in the maximum hot mode where all of the air having passed through the evaporator bypasses the heater core, and therefore, the cross sectional area of the cool air passage is set to be equal to that of the warm air passage.
In an air conditioning unit for a vehicle, there has been a demand to increase an amount of blowing air as much as possible in the maximum cool mode to improve cooling performance especially in summer. However, according to the air conditioning unit in the above-described Japanese Utility Model Publication, the amount of blowing air is restricted by the sliding door, because the surface at the air upstream side of the sliding door extends perpendicularly with respect to the flowing direction of the air passing through the evaporator in the maximum cool mode.